The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
Not applicable.
(1) Field of the Invention
This invention generally relates to a bottom activated retractable control surface for unmanned undersea vehicles.
More particularly, the invention relates to a bottom activated retractable control surface for unmanned undersea vehicles which is automatically retractable without user intervention.
(2) Description of the Prior Art
The current art for control fins on an unmanned undersea vehicle is not in question. However, the manner of retracting and deploying these control fins has not been addressed in the manner of the present invention. At the present time, if an unmanned undersea vehicle needs to rest on the bottom of the ocean, a standard control fin mounted on the underside of the vehicle can be seriously damaged due to this maneuver and its resulting contact on the ocean floor.
Thus, a problem exists in the art whereby damage occurs to the fins of the underwater vehicle during bottom maneuvers. The invention allows the lower quadrant fin(s) to retract as the unmanned underwater vehicle settles on the ocean bottom. Also when the vehicle is on the surface, the invention gives the capability of controlling surface maneuvering.
The following patents, for example, disclose various types of fins or rudders for underwater vehicles, but do not disclose automatically retractable fins as occurs in the present invention.
U.S. Pat. No. 1,246,475 to Schneider;
U.S. Pat. No. 3,093,105 to Rebikoff;
U.S. Pat. No. 3,752,105 to Hackett;
U.S. Pat. No. 3,805,540 to Crabille;
U.S. Pat. No. 3,902,441 to Scholle; and
U.S. Pat. No. 5,235,926 to Jones.
Specifically, the patent to Schneider discloses a submerging rudder for submarines. In particular, the device therein is for the purpose of causing submerging rudders of submarines to disappear or to be retracted during the periods in which they are not required to operate, and thus diminishing as far as possible the resistance offered by them to the progress of the vessel or partly into the interior of the hull. According to this invention the rudders which are capable of being retracted into a recess in the interior of the hull of the vessel, are rendered capable of pivoting, that is to say, of operating by rotation, after their protrusion from the said recess. For this purpose the rudder blade is mounted on a rudder shank which can be kept permanently retracted, and on which the rudder blade is adapted to slide for the purposes of being protruded and retracted. The rotation of the rudder shank carries around with it the sliding rudder blade and thus allows of rotating the latter for steering purposes as desired as soon as it has been moved out into its position of complete protrusion. Although the rudder retracts into the submarine, it does not automatically operate during an impact of the rudder against an obstacle. Instead, the rudder is manually retracted.
Crabille relates generally to boat rudders, and more specifically to an automatic flip-up rudder for use on air-boats and other boats wherein the rudder is the sole object which protrudes beneath the hull. The rudder is adapted to yieldably pivot in a vertical plane out of engagement with any obstruction which may be encountered. The rudder is mounted such that it will be automatically returned to an effective operating position after passing over the obstruction. Further, it should be understood that Crabille is a spring-loaded rudder that can xe2x80x9cbreak awayxe2x80x9d when striking an object and retract automatically when the object has been cleared. The retraction is exterior to the vehicle due to placement of the rudder at the outset, and any retraction/restoration does not affect the external volume of the vehicle. Instead, the rudder remains within the volume of water and does not alter the flowline of the vehicle.
The patent to Rebikoff relates to an arrangement applicable to submarine vessels in which there is provided a submarine vessel having a pair of fins (or hydroplane) for controlling the descent and ascent and stability of the vessel, wherein each fin is articulated about an axis substantially perpendicular to the plane of the fin, whereby the fin can fold back partially or wholly against the vessel on striking an obstacle against the action of resilient means which normally hold the fin in its proper position. The fins fold back when they strike an obstacle and once the obstacle has been cleared, regain their original position under the action of a restoring spring or equivalent means. When the fins are retracted totally or even partially, their action is evidently different from that in their normal position. The fins are always parallel to the direction of movement. The shock causing retraction is therefore always perpendicular to the shaft at which the fin is articulated and there is therefore no risk of deformation of this shaft. This patent, however, does not allow the fins to retract fully into the body of the vehicle. If bottom operation were desirable, the fins taught by Rebikoff cannot completely recess into the vehicle and damage would likely occur. Also, the fin could still interfere with an obstacle since the surfaces are still xe2x80x9cexposedxe2x80x9d when retracted.
The patent to Hackett discloses a rudder construction for small boats, particularly sail boats, in which the rudder is mounted on its rotatable support arm for pivotal movement on a horizontal axis to prevent damage to the rudder in the event that it strikes an obstruction in the water. A detent means yieldably retains the rudder in its normal vertical position or a horizontal or intermediate position. The tiller may be manipulated to move the rudder to any of a plurality of positions. More specifically, the design relates to a surface craft rudder that will move up into a set number of preset notches in the design. The device does not automatically return into its operating position after object impact and instead must be manually returned to an operating position. Further, the notched positions limit the number of positions of the rudder and an infinite number of positions within the fully extended and fully retracted range are not obtainable.
Scholle discloses a sailboat having retractable and self-ejectable hydraulic controls. A small lightweight sailboat of the type readily transported in passenger vehicles such as station wagons and the like is provided with hydraulic controls integrally and movably coupled to the hull of the sail-boat. The hydraulic controls comprise rudder and centerboard assemblages, each of which are pivotally coupled to the hull of the sailboat in a manner enabling them to be retracted and self-ejected when maneuvering the boat through shallow waters or over submerged obstacles. Due to the manner in which these hydraulic control assemblages are pivotally coupled to the hull of the sailboat, they can be fully retracted within the sailboat hull and onto the deck of the sailboat and secured in their fully retracted positions for storage when the sailboat is not in use or when preparing the sailboat for overland transport. Retraction and storage of the rudder assemblage is achieved by pivotally mounting the rudder at the stern of the sailboat in a manner which permits the rudder to be rotated onto and laid flat upon the deck. Retraction and storage of the centerboard assemblage is achieved by pivotally mounting a centerboard within a removable centerboard trunk in a manner which permits the centerboard to be locked within the centerboard trunk and released therefrom by controls housed within the trunk. Thus, the rudder hinges upward upon obstacle impact but does not return to operating position automatically. Although the centerboard does spring load in the retracted position upon an obstacle impact, manual intervention must be used to put the centerboard back in an operation position when reaching a fully retracted position. Further, the centerboard does not rotate for steering and thus cannot retract in a rotated position.
Jones discloses a pair of pivotally attached fins depending into the water below the hull of the boat. When turning maneuvers are executed, the tendency of the boat to skid sideward is resisted by the downwardly engaged fin panels. When underwater objects or the bottom of a body of water are encountered, the leading edge of the fins strike the objects(s), causing the fins to pivot upward to clear the obstacle(s) and then return automatically to the water to provide an extra measure of boating safety. The fins are not used for steering the vehicle and are simply hinged with no spring loading. The stabilizers re-enter the water due to the drag of two small wings extending normally from the stabilizer. These wings will xe2x80x9cgrabxe2x80x9d the water to pull the stabilizers back down into the water. Spring energy is not used herein and the stabilizers cannot rotate for steering.
In view of the prior art, there exists a need for providing a totally autonomous retraction control for a rudder that retracts out of the flow into the hull of the vehicle allowing bottoming of the vehicle with no damage to the rudder. The device should allow both low-speed control and high-speed maneuvering while allowing obstacle avoidance by permitting the rudder to bend out the way of debris.
Therefore it is an object of this invention to provide a bottom activated control device in an underwater vehicle.
Another object of this invention is to provide a bottom activated control device in an underwater vehicle which retracts fully within the hull of a vehicle.
Still another object of this invention is to provide a bottom activated control fin in an underwater vehicle in which the control fin is automatically retracted into the well portion of the underwater vehicle upon contact of the control fin with an outside force other than fluid.
A still further object of the invention is to provide a bottom activated control fin in an underwater vehicle in which the control fin is automatically retractable even if the control fin is rotated with respect to the longitudinal axis of the underwater vehicle.
Yet another object of this invention is to provide a bottom activated retractable control fin for an underwater vehicle which is simple to manufacture and easy to use.
In accordance with one aspect of this invention, there is provided a bottom activated retractable control device in an underwater vehicle. The device includes a fin member having a front edge, a trailing edge opposite to the front edge, a bottom edge between the front edge and the trailing edge, and an arm portion extending from and coextensive with the leading edge and away from the bottom edge. A pivot housing is provided for receiving the arm portion of the fin member, the housing enabling both a vertical pivot of the fin member upon contact of the fin with an object and axial rotation of the fin about the arm portion of the fin member. A well is formed in the bottom surface of the underwater vehicle, the well corresponding in depth to a fully retracted position of the fin member and in width to any rotated position of the fin member. A spring member extends through the pivot housing and the arm portion, the spring member normally biasing the fin member away from the vehicle, the fin member automatically retracting into as much as an entirety of the well in response to a force against the control fin.